1. Field of the Invention
The present invention relates to wireless communication, and more particularly, to a method and an apparatus for generating signals transmitted and received in a cellular network.
2. Related Art
In recent years, a service requiring ultra-high wireless communication such as wireless Internet has increased rapidly. As a result, a research into a communication technique that can ensure the ultra-high wireless communication for a next-generation wireless communication system has been actively progressed. Therefore, a lot of researches for a plurality of users to efficiently use resources including time, a frequency, a space, and the like for communication have been progressed. However, when more users are present than given resources, a high channel capacity for the ultra-high speed communication cannot be acquired due to interuser interference by the existing frequency division access, time-division access, and a code division access techniques, and the like.
Accordingly, in recent years, interference alignment (IA) technology in which a desired signal and undesired interference are divisionally transmitted to different spaces is proposed to turn over theoretical development on a transmission/reception technique in order to solve the problem that the high channel capacity cannot be acquired due to the interuser interference. It is certified that such a technique prevents performance deterioration by interference without complicated error correction encoding under a multi-user environment of a general interference channel and acquires a degree-of-freedom by maximizing the use of the given resources to thereby acquire the high channel capacity.
In detail, it is revealed that the interference alignment technique can almost achieve a channel capacity of an interference channel under a situation in which a signal-to-noise ratio is very high. The interference alignment technique is extended to the cellular network as well as the interference channel to be researched. It is revealed that in the cellular network constituted by two cells, users positioned in other cell may receive interference signals applied to a base station of a current cell to be arranged, and as a result, a lot of signal spaces for users for the current cell can be ensured. For example, when respective users transmit one stream, the users may allow an interference signal applied to the base station of other cell to be aligned and received in one-dimension signal space.